Fire-alarm apparatus



(No Model.) 2 Sheets-Sheet 1.

A. GQDAVIS. FIRE ALARM APPARATUS.

No. 488,388. Patented Dec. 20, 1892.

2 Sheets-Sheet 2.

(No Model.)

A. G. DAVIS. FIRE ALARM APPARATUS.-

m. 2% ma m MM ,A m Zw m MW Z a M n J 3 m6 w. 4 xm m im llNrrnn TATESPATENT FFlCEe AUGUSTUS Gr. DAVIS, OF BALTIMORE, MARYLAND.

FIRE-ALARM APPARATUS.

SPECIFICATION forming part of Letters Patent No. 488,388, dated December20, 1892.

Application filed May 27, 1892. Serial No. 434,570. (No model.)

To all whom it may concern.-

Be it known thatI, AUGUSTUS G. DAVIS, a citizen of the United States,residing at Baltimore, State of Maryland, have invented new and usefulImprovements in Fire-Alarm Apparatus; and I do hereby declare thefollowing to be a full, clear, and exact description of said invention,reference being had to the accompanying drawings, and to the letters ofreference marked thereon, which form a part of this specification.

My invention relates generally to fire alarm telegraphs and particularlyto the signal receiving apparatus located at the central station, enginehouse, or other place to which the message may be sent, the object ofmyinvention being to provide an improved alarmstriking mechanism whichwill indicate, by single strokes upon a suitable gong, the number of thesignal box sending in the alarm,

V and, my improvements consist essentially of the novel details ofconstruction and general arrangement of parts as Will be hereinafterfully described and specifically designated in the claims.

In the accompanying drawings, Figure 1 represents a front elevation ofan alarm-striking mechanism which embodies the essential features of myinvention. Fig. 2, a similar View of the same, with the front plate andstriking hammer removed to more fully show the train of spring-actuatedgears. Fig. 3 represents a detail View of the striking hammer, and Fig.at a detail view of the alarm checking mechanism.

Similar letters of reference occurring on the several figures of thedrawings indicate corresponding parts.

In carrying out my invention the alarm striking mechanism A is supportedupon a metallic skeleton frame 13 which, in its turn, is secured to asuitable backboard or support 0, the said frame B carrying a gong upon aforwardly extending post formed on its lower end. The striking mechanismA is springactuated, and consists of the large gear D, adapted to bedriven by the coiled spring a which imparts motion to the train ofgearing b, c, d, e, and f, all of said gears being suitably journaledwithin the framework E, E, and so arranged with relation to each otheras to impart a slow motion to the shaft F,

upon the gear b, and a rapid motion to the shaft G upon the gear f, whenthe mechanism is in operation.

'A disk H is mounted upon the forwardly projecting end of the shaft F;said disk be ing provided with a series of forwardly projecting studs orpins h, which are adapted to engage the hook-shaped end of the hammer I,which is pivoted near its upper end to the framework E; a coil spring c'being attached to the hammer and to an extensible arm i to increase thestrength of the blow of the hammer and produce a louder alarm upon thegong.

An electro-magnet K is secured to the skeleton frame B, just below thealarm striking mechanism, the armature L of said magnet being pivotednear its lower end to a projection g forming a part of the skeletonframe B. The one end of a coil springm is secured to the lower end ofsaid armature L and the opposite end to the regulating screw la, theobject of the same being to throw the armature away from the magnet whenthe circuit is open, to allow the free or upper end of the armature,which extends into the striking mechanism, to be there locked and stopthe mechanism until the circuit is closed to send in an alarm.

To. secure the armature in a locked position, when the circuit is open,I provide an arm M, which is suitably journaled at its one end withinthe framework E, E, and its opposite or free end being adapted to catchupon the top of the armature and there held by means of the stud orcatch N, upon the shaft G, bearing down upon the free end of said arm M.When the circuit is closed to send an alarm, the armature is attractedto the poles of the magnet and allows the free end of the arm M to drop,thereby releasing the stud or catch N and causing the train of gearingto be set in motion, thus revolving the studded disk H and tripping thehammer which strikes the gong and gives the alarm.

The number of the signal box sending in an alarm is automaticallyindicated by single framework E, and this arm 0 engages with a trip P,pivotally secured to an extension R upon the hook-shaped portion of thehammer I to lift the arm M in the path of the armature L and engage thesame to lock the striking mechanism each time that the circuit is brokenand said armature drawn away from the poles of the magnet. Each timethat the circuit is closed to release the-striking mechanism the hammerI descends to sound asingle stroke upon the gong, and in the operationof descending the point of the trip P projects under the arm 0 to liftthe arm M and engage with the armature L to lock the mechanism until thecircuit is again closed to sound another stroke upon the gong. Near thetop of the backboard or support 0, are provided the posts S, Sconnecting the magnet K with the line Wire.

Having thus described the construction and operation of my improvedapparatus, What I claim is:

1. An improved fire alarm apparatus composed of the striking mechanismA, the alarm checking mechanism consisting of the arms M and O, catch N,and the trip Pon the hammer I, and the magnets K and armature L,substantially as and for the purpose specified.

2. In an alarm operating mechanism, the hammer I provided with the tripP, in combinations with the arms M and O, armature L, magnet K, catch N,and the train of gearing, all substantially as and for the purposeSpecified.

In testimony whereofIaffiX my signature in presence of two subscribingwitnesses.

AUGUSTUS G. DAVIS. [L. s.]

Witnesses:

J NO. B. MARsHALL, CHAS. A. BOYLAN.

